Foldable sheet



A. o. PALM FOLDABLE SHEET Oct. 17, 1950 2 Shee'ts-Sheet 1 File@ June 29, 1943 www,

3 5 .af ,n /fl @la Oct. 17, 1950 A. o. PAI- M FQLABLE SHEET Filed June 29, 1948 2 Sheets-Sheet 2 Patented Oct. 17, 1950 FOLDABLE SHEET Anders Oswald Palm, Stockholm, Sweden, as-

signor of one-half to Nils Gustaf Hoglander and Torsten Frans Moberg, both of Stockholm,

Sweden Application June 29, 1948, Serial No. 35,839 In Sweden March 18, 1947 claim-s1 (o1. 281-1) This invention relates to foldable sheets to be used as foldable maps, diagrams, programs, etc.

It is an object of the invention to provide a foldable sheet which may be easily be folded together so as to occupy only a fraction of the space which it occupies in the unfolded state.

Another object of the invention is to provide a foldable sheet which may be unfolded or folded together by a single turn.

A further object is to provide a foldable sheet arranged in a cover which, when Opened, causes the sheet to be automatically unfolded, so that the whole of the map or the like is visible, and, when closed, automatically folds the sheet so that the same will be contained within the borders of the closed cover.

These objects are achieved by providing the sheet with folds in the manner described hereinafter.

Five embodiments of the foldable sheet `according to the present invention are described hereinafter with reference to the accompanying drawings, wherein:

Fig. 1 is a plan View of the rst embodiment of the foldable sheet in the unfolded state;

Fig. 2 illustrates an intermediate stage of the folding operation;

Fig. 3 is a side View of the closed cover and Figs. 4 to 6 are plan views of modifications of the foldable sheet in the unfolded state.

From the centre O of the square sheet I Fig. 1, diagonal or secondary folding lines extend to `each of the four corners. The portions'of these folding lines which are nearest to the centre, i. e. the portions O-A, O-B, O-C and O-'D, are `directed towards the rear side of the sheet, whereas the remaining, or outer, portions A-Ai, B-B1, C-C1 and D-Di thereof are directed towards the front side of the sheet. The term directed to is used here to indicate that the edge, or ridge, of the fold is on the rear side or on the front side of the sheet, respectively. From the junction points A, B, C and D ofthe two portions of each diagonally extending folding line forming the half of Aa `complete diagonal, two folding lines AE, A-E1, B-F, BF1, C-G, C-Cn and D-H, D-H1 respectively, extend parallel to adjacent edges of the sheet I. These folds are directed towards the rear side of the sheet similarly as the inner portions of thediagonal folds. Finally there is a central or primary folding line II1 which extends through the centre O of the sheet parallel to two of its edges thus bisecting the angle between the diagonal folds. This central fold I-I1 is directed towards the front side of the sheet. In the drawings the folds directed towards the front side of the sheet are shown in dotted lines, whereas the folds directed towards its rear side are indicated by dots and dashes.

If desired, the sheet I may be provided with a cover whose front and back portions are denoted 2 and 2', respectively. The fold of the cover has the reference numeral 3 (Figs. 2 and 3). The sheet I is so arranged in the cover that its central fold I-Ii coincides with the fold 3 of the cover. The sheet may be attached to the cover over the whole, or parts, of the surfaces designated ODHEA and OBFGC, such as by glueing, sew# ing, stitching etc. The front edges of the cover suitably extend beyond the borders of the sheet I, as shown in Fig. 2, these projecting portions :being intended to be gripped between the thumb and the fore-finger of each hand when it is desired to open or to close the cover. Owing to the particular folding tendency imparted to the sheet I through the above-mentioned folds, the sheet I will be automatically unfolded when the cover 2, 2' is opened (Fig. l) and will be automatically folded together to a small Size contained entirely within the borders of the cover when the latter is closed. Fig, 2 shows an intermediate stage in the folding operation. When folded together, the contour of the sheet I is OAEHD, see Fig. 3.

The height of the cover 2, 2 should be substantially equal t0, or somewhat greater than, one third of the edge of the square sheet, and the width of each cover portion should be substantially equal to, or somewhat greater than, one half of said edge.

Fig. 4 illustrates the invention as applied to a sheet of rectangular shape. The only difference as compared with the embodiment shown in Fig. l is that the secondary folds O1-A1, O1-B1 and Oz-Cn O2--D;, respectively, extend in pairs from two spaced points O1 and O2, respectively, on the central folding line I-Ii. The portion of said folding line which is situated between the two points O1 and Oz is directed towards the rear side of the sheet I.

According to Fig. 5 the lines Ai-Cl and Bi-Di crossing each other at right angles at the centre O intersect opposite edges of the `sheet I at some distance from the corners. The sheet is rectangular. i

Fig. 6 shows a rectangular sheet I whose primary, or central folding line I-I1 is parallel to the short edge of the sheet. Of the two supplementary folding lines extending from the junc` tion points A, B, C, D of the diagonal fold portions one stands perpendicularly on the edge of 3 the sheet whereas the other A-E1, B-Fi, C-G1, D-H1 forms an angle with the edge.

In Figs. 4 6 covers 2, 2 are also shown for the sheet l. When these covers are closed the sheets will be automatically folded together in a similar manner as described in connection with Fig. 1.

Thus, through my invention a foldable map, diagram, program, etc., is obtained which may be folded together and unfolded in a very simple and convenient manner. In the folded state the sheet occupies a very small space, and thus a map or the like may be made which can easily be put into a vest-pocket. However, the invention may be applied also to sheets of a larger size.

According to further embodiment of my invention the foldable sheet may consist also of one half only of a sheet of the above described types cut along a line perpendicular to the central or primary, folding line I-Ii and passing through the centre O (Figs. 1, 5, 6) cr midway between the two points Oi, O2 (Fig. 4). This sheet will be of an elongate shape.

Various other modifications are conceivable within the scope of the appended claims. Thus, portions of the sheet may be cut away and the edges of the sheets may be formed in different ways.

As an example of how the sheet is folded, the following may be carried out.

A piece of paper is placed upon a somewhat soft base and the folding lines are marked or impressed by means of a pointed instrument and a rule. The sheet is first placed with its back side on the soft base whereupon the folding lines O-A, O-C, O-D and A-E, A-Ei, B-F, B-Fi, C-G, C-Gi, D-I-I, D-Hi are impressed. The sheet is then turned so that its front side rests on the soft base whereupon the remaining folding lines, viz. I-I and A-Ai, B-BL C-C1, D-Di, are impressed by means of the pointed instrument. The sheet thus prepared is then folded by hand in accordance with the pre-formed folding lines which is quite easy. Of course, the folding could also be accomplished in a suitable machine.

What I claim is:

1. In a square foldable sheet, diagonal folding lines extending from each of the four corners to the centre of the sheet, a central folding line extending from one edge of the sheet to the opposite edge thereof and bisecting the angle between the diagonal folding lines, and supplementary folding lines extending from adjacent edges of the sheet perpendicularly to the same and meeting in pairs on the diagonal folding lines, the folding direction of the central folding line and the portions of the diagonal folding lines outside the points of intersection with the supplementary folding lines being the same and opposite to that of the remainder of the folds.

2. In a rectangular foldable sheet, a central folding line extending from one edge of the sheet to the opposite edge thereof through the centre and parallel to the long' edge of the sheet, a folding line extending from each corner of the sheet obliquely inwards and meeting in pairs at two spaced points on the central folding line, and supplementary folding lines extending from adjacent edges of the sheet perpendicularly to the same, said supplementary folding lines meeting in pairs on each of the obliquely extending folding lines, the folding direction of the portions of the central folding line outside the two abovementioned spaced points thereon and of the portions of the obliquely extending folding lines outside the points of intersection with the supplementary folding lines being the same and opposite to that of the remainder of the folds.

3. In a rectangular foldable sheet, diagonal folding lines extending from each of the four corners to the centre of the sheet, a central folding line extending parallel to the short edge of the sheet and bisecting the angle between the diagonal folding lines, and supplementary folding lines extending from adjacent edges of the sheet and meeting in pairs on each of the diagonal folding lines, one supplementary folding line in. each pair being parallel to the long edge of the sheet and the other forming an angle with the short edge of the sheet, and the folding direction of the central folding line and the portions of the diagonal folding lines outside the points of intersection with the supplementary folding lines being the same and opposite to that of the remainder of the folds.

4. In a foldable sheet, a primary folding line extending across the sheet, four secondary folding lines extending from the edges of the sheet and meeting in pairs on the primary folding line which bisects the angle between the secondary folding lines of each pair, and eight supplementary folding lines extending in pairs from points of intersection on each of the secondary folding lines on opposite sides thereof to the edges of the sheet, the folding direction of the primary folding line and the secondary folding lines outside the points of intersection thereof with the pairs of supplementary folding lines being the same and opposite to that of the remainder of the folding lines.

5. In a foldable sheet, a primary folding line extending across the sheet, four secondary folding lines extending from the edges of the sheet and meeting in pairs on the primary folding line which bisects the angle between the secondary folding lines of each pair, eight supplementary folding lines extending in pairs from points of intersection on each of the secondary folding lines on opposite sides thereof to the edges of the sheet, the folding direction of the primary folding line and the secondary folding lines outside the points of intersection thereof with the pairs of supplementary folding lines being the same and opposite to that of the remainder of the folding lines, and a foldable cover for said foldable sheet, the primary folding line of the sheet coinciding with` the fold of the cover and the sheet being attached to said cover on opposite sides of the central fold thereof.

ANDERS OSWALD PALM.

REFERENCES CITED UNITED STATES PATENTS Name Date Boyer Mar. 24, 1925 Number 

